【bzoj3531】[SDOI2014]旅行

#include<cstdio>
#include<iostream>
#include<cstring>
#include<string>
#include<algorithm>

using namespace std;
const int N=100010;
char s[3];
int qx,n,m,te,sz,q,tot;
int num
,size
,tree
,val
,w
,c
;
int head
,son
,fa
,h
,tp
,root
;
struct edge{
int v,next;
}e[200010];
struct seg{
int sum,mx;
int l,r,lch,rch;
}tr[2000010];
inline int F()
{
register int aa,bb;register char ch;
while(ch=getchar(),(ch<'0'||ch>'9')&&ch!='-');ch=='-'?aa=bb=0:(aa=ch-'0',bb=1);
while(ch=getchar(),ch>='0'&&ch<='9')aa=(aa<<3)+(aa<<1)+ch-'0';return bb?aa:-aa;
}
void add(int u,int v)
{
e[++te].v=v;
e[te].next=head[u];
head[u]=te;
}
void dfs1(int x)
{
size[x]=1;
for (int i=head[x];i;i=e[i].next)
{
int v=e[i].v;
if (v==fa[x])continue;
fa[v]=x;
h[v]=h[x]+1;
dfs1(v);
size[x]+=size[v];
if (size[v]>size[son[x]])son[x]=v;
}
}
void dfs2(int x,int chain)
{
tp[x]=chain;
num[x]=++sz;
if (!son[x])return;
dfs2(son[x],chain);
for (int i=head[x];i;i=e[i].next)
{
int v=e[i].v;
if (v==fa[x]||v==son[x])continue;
dfs2(v,v);
}
}
void updata(int k)
{
tr[k].sum=tr[tr[k].lch].sum+tr[tr[k].rch].sum;
tr[k].mx=max(tr[tr[k].lch].mx,tr[tr[k].rch].mx);
}
void build(int &k,int l,int r,int x,int v)
{
int mid=(l+r)>>1;
if(!k)k=++tot;
tr[k].l=l,tr[k].r=r;
if (l==r)
{
tr[k].sum=v;
tr[k].mx=v;
return;
}
if (x<=mid)build(tr[k].lch,l,mid,x,v);
else build(tr[k].rch,mid+1,r,x,v);
updata(k);
}
void querysum(int k,int x,int y)
{
int l=tr[k].l,r=tr[k].r;
if (!k)return;
if (x<=l&&r<=y)
{
qx+=tr[k].sum;
return;
}
int mid=(l+r)>>1;
if (x<=mid)querysum(tr[k].lch,x,y);
if (y>mid)querysum(tr[k].rch,x,y);
}
void querymax(int k,int x,int y)
{
int l=tr[k].l,r=tr[k].r;
if (!k)return;
if (x<=l&&r<=y)
{
qx=max(qx,tr[k].mx);
return;
}
int mid=(l+r)>>1;
//  getchar();
//  cout<<k<<' '<<x<<' '<<y<<' '<<l<<' '<<r<<' '<<mid<<endl;
if (x<=mid)querymax(tr[k].lch,x,y);
if (y>mid)querymax(tr[k].rch,x,y);
}
int solvesum(int x,int y,int st)
{
qx=0;
while(tp[x]!=tp[y])
{
if (h[tp[x]]<h[tp[y]])swap(x,y);
querysum(root[st],num[tp[x]],num[x]);
x=fa[tp[x]];
}
if (num[x]>num[y])swap(x,y);
querysum(root[st],num[x],num[y]);
return qx;
}
int solvemax(int x,int y,int st)
{
qx=0;
while(tp[x]!=tp[y])
{
if (h[tp[x]]<h[tp[y]])swap(x,y);
//      cout<<111111111<<endl;
querymax(root[st],num[tp[x]],num[x]);
x=fa[tp[x]];
}
if (num[x]>num[y])swap(x,y);
//  cout<<22222222<<endl;
querymax(root[st],num[x],num[y]);
return qx;
}
int main()
{
int u,v,x,C,y;
n=F(),q=F();
for(int i=1;i<=n;++i)
w[i]=F(),c[i]=F();
for (int i=1;i<n;++i)
u=F(),v=F(),add(u,v),add(v,u);
h[1]=1;dfs1(1);dfs2(1,1);
for (int i=1;i<=n;++i)
build(root[c[i]],1,n,num[i],w[i]);
for (int i=1;i<=q;++i)
{
scanf("%s",s);x=F(),y=F();
if (s[0]=='C'&&s[1]=='C')
{
build(root[c[x]],1,n,num[x],0);
build(root[y],1,n,num[x],w[x]);
c[x]=y;
}
else if (s[0]=='C'&&s[1]=='W')
{
build(root[c[x]],1,n,num[x],y);
w[x]=y;
}
else if (s[0]=='Q'&&s[1]=='S')
printf("%d\n",solvesum(x,y,c[x]));
else if (s[0]=='Q'&&s[1]=='M')
printf("%d\n",solvemax(x,y,c[x]));
}
}